Add multiple clause and tree level optimizations

Implement optimizations that can be called in parallel or serial.
Optimizations occur mostly in place and result in a logically equivalent
tree when used correctly.

Optimizations
=============

* Sort - sort all statements within a clause tree
* Simplify - apply negation rules to all statements
* Flatten - merge child clauses with parents
* Compact - merge equivalent statements
* Tidy^ - remove zero statements
* Contradictions - zero contradicting statements and clauses
* StrictEquality - zero fuzzy statements when exact statements are within
  clause
* Tighten - combine multiple fuzzy statements to the least (AND) or
  most (OR) restrictive bounds

^: when used incorrectly can turn an invalid clause tree into a valid
one

1 files changed, 1 insertions, 1 deletions

diff --git a/pkg/query/lexer.go b/pkg/query/lexer.go
index 4d875fb..759b5bc 100644
--- a/pkg/query/lexer.go
+++ b/pkg/query/lexer.go
@@ -340,6 +340,6 @@ func init() {
 	LexRegexPattern = clausePattern
 
 	// FIXME: fails to match start of clauses with no values
-	//        ex: (and (or ... )) fails
+	//        example: (and (or ... )) fails
 	LexRegex = regexp.MustCompile(LexRegexPattern)
 }